<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>iframe流</title>
</head>
<body>
<div id="clock"></div>
<iframe src="http://localhost:8000/clock" frameborder="0" style="display: none"></iframe>

<script>
  // window.setTime =
  // ↕等价
  function setTime(ts) {
    document.querySelector('#clock').innerHTML = ts;
  }
</script>
</body>
</html>
